California heads toward requiring solar panels on all new houses

California is set to require solar panels on all newly built single-family houses, the first statewide mandate in the nation. That's expected to save buyers money in the long run, but will raise their upfront costs at a time many are already struggling to afford a mortgage.

The state's Energy Commission is scheduled to vote Wednesday on the rules, which are expected to pass and take effect in 2020. The rules, which would also apply to new multifamily buildings of three stories or less, don't need the approval of the Legislature.

The package follows other code updates that have already made new homes and commercial buildings greener in recent years, including when regulators in 2012 required roofs be built so that solar panels could easily be added.

The mandates, which have gained support from the construction industry, also include new insulation and air filter requirements and are part of a larger effort to update building standards in order to use new structures as a weapon against climate change.